Blood transfusions are used to treat many disorders and injuries, such as in the treatment of accident victims and during surgical procedures. According to current American Red Cross statistics, about 5 million people receive blood transfusions each year, in the United States alone. Thus, health care systems rely on the collection and distribution of blood. Typically, blood is obtained from a donor and then processed and stored; units of stored blood or blood products are then taken from storage as needed and transfused into a patient in need. In some cases, the blood may be an autologous donation, where an individual donates blood in expectation of receiving his or her own blood by transfusion during a medical procedure.
Donated blood is typically processed into components and then placed in storage until needed. When a subject is in need of a blood transfusion, a unit of blood is commonly removed from storage, rejuvenated, washed, and re-suspended in an appropriate solution. In some instances, the red blood cells were lyophilized prior to storage, in which case they need to be re-suspended, washed, and then re-suspended again in an appropriate solution. The re-suspended red blood cells are then transfused into the subject. In either scenario, washing the red blood cells is traditionally a tedious, time consuming and multistep process that requires a great deal of tubing, and the use of expensive centrifuges with rotating seals to separate the cells from the wash solution. Therefore, there remains a need to streamline and simplify the process for washing red blood cells prior to transfusion.